1. Field of the Invention
The present invention relates generally to fitting out trunking of the type used to house and protect various devices, in particular electrical devices, and to house and protect cables, conductors or other lines to which they are connected.
2. Description of the Prior Art
Hereinafter, in the usual way, the term xe2x80x9ctrunkingxe2x80x9d refers to the combination of a base section, which has an open cross section, and at least one cover section, which is adapted to be attached to the base section, for example clipped to it, to close it.
The base section usually has a back which is adapted to be attached to some kind of support, for example an inside or outside wall, one or more longitudinal walls, for example a lateral flange when its cross section is U-shaped or L-shaped, and at least one fixed or removable internal partition if its internal volume is divided transversely into two or more compartments.
The present invention relates more particularly to retaining clips for use with trunking of the above kind and which are adapted to be attached transversely to the base section of the trunking, from place to place, to close locally and at least partly at least one of the compartments of the base section, in order temporarily to retain cables or conductors placed in the compartment or already present therein pending fitting of the corresponding cover section, or while it is removed.
The retaining clips are of two kinds.
The first kind of retaining clip extends cantilever-fashion from any longitudinal wall of the base section.
This is the case, for example, in German patent No. 24 15 768, in which the longitudinal wall in question is a rim on a lateral flange of the base section and parallel to its back.
However, in the above German patent application, each retaining clip is essentially no more than a simple flap rotatably mounted on the longitudinal wall.
Apart from the fact that rotary mounting is suitable only for trunking whose base section is designed accordingly, it cannot provide stable retention of the retaining clips in the various positions that they can assume.
Retaining clips of the second type extend from one to the other of two longitudinal walls of the base section, which is therefore used to hold them in position.
This is the case, for example, in German patent application No. 2 326 348 in which, as previously, the retaining clips are essentially no more than a flap articulated to one of the two longitudinal walls of the base section concerned, but are additionally provided with a clip for releasably locking them to the other longitudinal wall, which incorporates an opening for this purpose, in this case a keyhole shaped opening, into which the clip is inserted.
Apart from the fact that the provision of the spaced openings in the base section can hardly fail to complicate its manufacture considerably, the retaining clips are relatively difficult to handle and fit.
This problem is aggravated by the fact that the retaining clips have to slide parallel to their rotation axis for their clip to engage in the narrower part of the corresponding opening in the base section.
In published French patent application No. 2 651 387, which is concerned with a cover section joint rather than a retaining clip, the retaining clips are substantially rigid parts requiring temporary deformation of the base section to fit them, the two longitudinal walls of the base section between which they extend having to be spread apart to enable them to be clipped to them.
Substantially the same can be said of German patent application No. 34 41 377.
Published international patent application No. WO98/10499 describes a retaining clip adapted to extend from one to the other of two longitudinal walls of the base section of the trunking.
However, in published international patent application No. WO98/10499, the retaining clip includes a fixing base adapted to be attached locally to one of the longitudinal walls and a retaining flap which is articulated to the fixing base and can move between a standby position, in which it provides unrestricted access to the underlying interior volume of the base section, and a service position, in which it closes the interior volume at least partly, interengaging with the other of the longitudinal walls concerned of the base section, in practice clipping to it.
Accordingly, in international patent application No. WO98/10499, the retaining flap of the retaining clip must have its length adapted to the width of the compartment(s) of the base section to be closed and, to hold the retaining flap in a stable service position, the base section must itself be adapted to enable the necessary clipping action.
Finally, in European patent application No. 0 838 885, clipping is advantageously avoided, and in the service position the free end of the retaining flap of the retaining clip, i.e. the end opposite the fixing base, merely engages behind a longitudinal wall of the base section of the trunking, in this instance the rim of one of the lateral flanges of the base section, and bears on that longitudinal wall.
However, as previously, the length of the retaining flap must be adapted to the width of the compartment(s) to be closed.
Finally, moving it to the service position requires temporary deformation of the base section, which makes using the system complicated.
A general object of the present invention is an arrangement which avoids the various drawbacks referred to above, in a very simple manner.
To be more precise, it provides a retaining clip for trunking, of the kind including, on the one hand, a fixing base adapted to be attached locally to any longitudinal wall of the base section of such trunking, such as an internal partition or a lateral flange of the base section, for example, and, on the other hand, a retaining flap which is articulated to the fixing base and can therefore move from a standby position, in which it allows unrestricted access to the underlying interior volume of the base section, to a service position, in which it closes that interior volume at least partly, then extending substantially transversely relative to it, including, independently of any member or component of the base section or of the trunking, releasable locking means for locking the retaining flap in its service position.
In other words, in accordance with the invention, the retaining flap is held in a stable service position without the base section to which the retaining clip is attached having to interact in any way with the end of the retaining flap opposite the fixing base.
The locking means are advantageously adapted to create a sticking point on the trajectory of the retaining flap on respective opposite sides of which said retaining flap is stable in its service and standby positions.
For example, the autonomous releasable locking means include at least one locking bead projecting from the fixing base and at least one locking tongue on the retaining flap which is in corresponding relationship to the aforementioned locking bead and adapted to be moved from one side of the locking bead to the other to engage under it.
Be this as it may, whilst being able to extend, if required, from one to the other of two longitudinal walls of the base section of the trunking, the retaining clip according to the invention in practice extends cantilever-fashion from one of the longitudinal walls and, despite the resulting overhang, is advantageously capable of holding its retaining flap in a stable service position, thanks to the autonomous releasable locking means with which it is equipped for this purpose in accordance with the invention.
Accordingly, an advantageous compromise is achieved between allowing an overhang of a retaining clip of the above kind, so that its retaining flap can have a length independent of the width of the compartment(s) to be closed, and stable retention of the retaining flap in the service position, with no risk of it rotating unintentionally if the cables or conductors in the compartment(s) it closes apply a force to it in the direction that would otherwise open it.
In a different embodiment, the releasable locking means of the retaining flap include a bistable hinge which passes through a sticking point between two stable positions of the retaining flap, i.e. its service position and its standby position.
The bistable hinge advantageously forms spring return means for the retaining flap operative between the sticking point and its original stable position.
Furthermore, the retaining clip according to the invention does not rely on the base section to which it is attached to hold its retaining flap in the service position, and therefore has the advantage of being particularly fast and simple to use.
Finally, requiring no adaptation of the base section to hold the retaining flap, it has the advantage of being adapted to be fitted in a quasi-universal manner to base sections of different kinds, which widens its field of application.
The features and advantages of the invention will emerge further from the following description, which is given by way of example, and with reference to the accompanying diagrammatic drawings.